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Strength reduction factors for seismic analyses of buildings exposed to near-fault ground motions

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Earthquake Engineering and Engineering Vibration 2011年第2期10卷 195-209页

作者： Qu Honglue Zhang Jianjing J.x. zhao School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China Institute of Geological ＆ Nuclear Sciences PO Box 30-368 Lower Hutt New Zealand

To estimate the near-fault inelastic response spectra, the accuracy of six existing strength reduction factors （R） proposed by different investigators were evaluated by using a suite of near-fault earthquake records with directivity-induced pulses. In the evaluation, the force-deformation relationship is modelled by elastic-perfectly plastic, bilinear and stiffness degrading models, and two site conditions, rock and soil, are considered. The R-value ratio （ratio of the R value obtained from the existing R-expressions （or the R-p-T relationships） to that from inelastic analyses） is used as a measurement parameter. Results show that the R-expressions proposed by Ordaz ＆ Perez-Rocha are the most suitable for near-fault ground motions, followed by the Newmark ＆ Hall and the Berrill et al. relationships. Based on an analysis using the near-fault ground motion dataset, new expressions of R that consider the effects of site conditions are presented and verified.

关键词： strength reduction factors near-fault ground motion response spectra force-deformation relationship

Wenchuan Post-earthquake Reconstruction by Utilizing Composite Tubular Construction and FRP Retrofitting Technology

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四川大学学报（工程科学版） 2009年第3期41卷 231-247页

作者： zhao x L AL-MAHAIDI R Dept. of Civil Eng. Monash Univ. Clayton VIC 3800 Australia

This paper presents two possible construction methods that could be adopted in the Wenchuan post-earthquake *** is the composite tubular construction and the other is FRP(Fibre Reinforced Polymer) retrofitting *** background of these two methods,the existing research and relevance to Whenchuan post-earthquake reconstruction are described.

关键词：抗振结构建筑结构建筑物 FRP 地震重建

4D spinless topological insulator in a periodic electric circuit

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National Science Review 2020年第8期7卷 1288-1295页

作者： Rui Yu Y.x.zhao Andreas P.Schnyder School of Physics and Technology Wuhan University National Laboratory of Solid State Microstructures and Department of Physics Nanjing University Collaborative Innovation Center of Advanced Microstructures Nanjing University Max-Planck-Institute for Solid State Research

According to the mathematical classification of topological band structures, there exist a number of fascinating topological states in dimensions larger than three with exotic boundary phenomena and interesting topological responses. While these topological states are not accessible in condensed matter systems, recent works have shown that synthetic systems, such as photonic crystals or electric circuits, can realize higher-dimensional band structures. Here, we argue that, because of its symmetry properties, the 4D spinless topological insulator is particularly well suited for implementation in these synthetic systems. We explicitly construct a 2D electric circuit lattice, whose resonance frequency spectrum simulates the 4D spinless topological insulator. We perform detailed numerical calculations of the circuit lattice and show that the resonance frequency spectrum exhibits pairs of 3D Weyl boundary states, a hallmark of the nontrivial topology. These pairs of 3D Weyl states with the same chirality are protected by classical time-reversal symmetry that squares to +1, which is inherent in the proposed circuit lattice. We also discuss how the simulated 4D topological band structure can be observed in experiments.

关键词： topological circuit 4D topological states 4D topological Hall effect second Chern number Weyl states

Time-dependent treatment of intramolecular energy transfer for HeICl complex

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Chinese Journal of Chemistry 1997年第3期15卷 218-224页

作者： zhao, x Bu, Yx Wu, AL Guan, DR SHANDONG NORMAL UNIV DEPT PHYSJINAN 250014SHANDONGPEOPLES R CHINA

The time-dependent golden wave packet method has been used for calculating the decay widths of vibrational predissociation for HeICl complex in the B state with total angular momentum J=0. This is a good example of intramolecular energy transfer, We examine the dependence of the final rotational distribution (partial decay width) of ICI fragment an the stretching excitation. It is found that computed final rotational distributions are weakly dependent on the vibrational level being excited. Unlike the smoothly varying rotational distribution for lower initial vibrational levels, for higher initial vibrational levels the rotational distribution indicates the very pronounced oscillatory structure. The analysis of the rotational distribution as a function of propagation time reveals the predominant role of the final states interaction in determining the final rotational distribution.

关键词： vibrational predissociation time-dependent wave-packet propagation

MORPHOLOGY AND ORIENTATION CHARACTERISTICS OF DIRECTIONALLY SOLIDIFIED α(A1)-Mg_2Si EUTECTIC

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Acta Metallurgica Sinica(English Letters) 1996年第5期9卷 323-328页

作者： S.P.Li S.x.zhao M.x Pan D.Q.zhao x.C.Chen Institute of Physics Chinese Academy of SciencesBeijing 100080China

Dependence of the morphology of α(Al)-Mg2Si eutectic on the solidification velocity, and its orientation characteristics were investigated by thermoanalysis, directional solidification and electron diffraction techniques in this *** eutectic morphology transformed from lamellae to rods with the increasing of the solidification velocity. Simultaneously, the orientation relationship changed from (100)Mg2Si/(100)Al;[110]Mg2si/[110]al to (011)Mg2si/(121)Al;[111]Mg2Si/[111]Al and (010)Mg2Si/(110)Al; [100]Mg2Si/[111]Al. Transformation of the eutectic morphology was related to the change of the preferred orientation of phase Mg2si.

关键词： ?Al)-Mg2Si eutectic orientation directional solidification

Machine learning guided automatic recognition of crystal boundaries in bainitic/martensitic alloy and relationship between boundary types and ductile-to-brittle transition behavior

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Journal of Materials Science & Technology 2021年第25期84卷 49-58页

作者： x.C.Li J.x.zhao J.H.Cong R.D.K.Misra x.M.Wang x.L.Wang C.J.Shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Department of Metallurgical Materials and Biomedical EngineeringUniversity of Texas at El Paso500 W.University AvenueEl PasoTX 79968USA

Gradient boosting decision tree(GBDT)machine learning(ML)method was adopted for the first time to automatically recognize and conduct quantitative statistical analysis of boundaries in bainitic microstructure using electron back-scatter diffraction(EBSD)*** spite of lack of large sets of EBSD data,we were successful in achieving the desired accuracy and accomplishing the objective of recognizing the *** with a low model accuracy ofxis-angle pair as characteristic features,the accuracy of the model was significantly enhanced to about 88%when the Euler angle was converted to overall misorientation angle(OMA)and specific misorientation angle(SMA)and considered as important *** this model,the recall score of prior austenite grain(PAG)boundary was~93%,high angle packet boundary(OMA>40°)was~97%,and block boundary was~96%.The derived outcomes of ML were used to obtain insights into the ductile-to-brittle transition(DBTT)***,ML modeling approach suggested that DBTT was not determined by the density of high angle grain boundaries,but significantly influenced by the density of PAG and packet *** study underscores that ML has a great potential in detailed recognition of complex multi-hierarchical microstructure such as bainite and martensite and relates to material performance.

关键词： Machine learning Feature engineering Automatic recognition Lath structure Crystallography

A COLUMN RECURRENCE ALGORITHM FOR SOLVING LINEAR LEAST SQUARES PROBLEM

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Journal of Computational Mathematics 1996年第4期14卷 301-310页

作者： J.x. zhao(Department of Mathematics, Nanjing University, Nanjing China) NANJING UNIV DEPT MATHNANJING 210008PEOPLES R CHINA

A new column recurrence algorithm based on the classical Greville method and modified Huang update is proposed for computing generalized inverse matrix and least squares solution. The numerical results have shown the ... 详细信息

关键词： Math A COLUMN RECURRENCE ALGORITHM FOR SOLVING LINEAR LEAST SQUARES PROBLEM ABS

Empirical models for predicting lateral spreading considering the effect of regional seismicity

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Earthquake Engineering and Engineering Vibration 2012年第1期11卷 121-131页

作者： Zhang Jian Yang Changwei John x. zhao Graeme H. Mcgerry Department of Civil Engineering Southwest Jiaotong University Chengdu 610031 China GNS Science Lower Hutt New Zealand

A revised empirical model has been developed for predicting liquefaction-induced lateral spreading displacement （LD） as a function of both response spectral acceleration derived from strong-motion attenuation models and geotechnical parameters from Youd＇s LD data set （Youd website）. This revised model is different from the model of Zhang and zhao, which overcame some drawbacks of earlier models for predicting lateral spreading and was primarily used in Japan and the western U.S. The revised model can potentially be applied anywhere if ground shaking （in terms of 5% damped acceleration or displacement response spectra） can be estimated using local strong-motion attenuation relationships. The revised model is examined using data from Japan and the western U.S. and applied to Turkey and New Zealand, where the ground shaking is estimated using appropriate strong-motion attenuation relationships for each region. The accuracy of the revised model is evaluated by comparing its predicted lateral displacements with those measured in actual earthquakes. The results show that the revised model can account for the effects of local seismicity on lateral spreading displacements and is comparable with existing prediction models.

关键词： lateral spreading liquefaction strong-motion attenuation

THE REINFORCING MECHANISM OF TiB2 IN TiB2/A357 COMPOSITE

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Acta Metallurgica Sinica(English Letters) 2003年第5期16卷 375-378页

作者： B.Yu Y.J.Zhang Z.x.zhao~ F.x.zhao: Q.K.Cai C.S.Liu ShenyangResearchInstituteofFoundry TheChineseAcademyofMachinerySciencesShenyang110022China EastChinaUniversityofScienceandTechnology Shanghai200237China SchoolofMaterials&Metallurgy NortheasternUniversityShenyang110004China

Mechanical properties were tested for in situ TiB2/A357 composite fabricated by LSM (mixed salts reaction) method. Micro structures of as cast and plastic deformed TiB2/A357 were investigated. The results show that there is a low misfit between (200) Al and (101)TiB2 with [011]//Al [101]TiB2. There is a change from fully dendritic structure of the α-Al of A357 to a rosette-type structure of TiB2/A357. Significant increases in proof stress and Young's modulus can be obtained at low TiB2 additions. There exist dislocation loops around neighboring TiB2 particles with about 0.1μm in diameter and dislocation multiplication near TiB2 particles.

关键词： TiB2/Al in situ composite reinforcing mechanism